Semiconductor packaging utilizes bumps to establish electrical contact between a chip's Input/Output (I/O) pads and a substrate. Structurally, a bump structure contains a bump and a so-called under bump metallurgy (UBM) located between the bump and an I/O pad. The bumps themselves, based on the material and shape, are classified as solder balls, pillar bumps and metal bumps with mixed metals. Recently, instead of using solder balls, pillar bumps are used in the electronic component to achieve finer pitch with minimum probability of bump bridging, and to reduce capacitance load for the circuits and allow the electronic component to perform at higher frequencies. A solder alloy is still necessary for capping the bump structure and joining electronic components as well. Properly applied, pillar bumps can be placed in virtually any position on a chip, given the pitch considerations. In addition, redundant bumps can be added for symmetry, mechanical stability, additional thermal arrangement, or to optimize interconnect to reduce inductance and enhance speed.